Die stock



Dec. 20, 1949 JOHNSQN 2,491,665

DIE STOCK Filed Sept. 11, 1946 1 .1 12 1 16 c w 3 i w E 1.5 D T i IN VEN TOR.

ATTORNEY KMQAWLQ Patented Dec. 20, 1949 DIE STOCK Edward H. Johnson,Westwood, Mass., assignor to Achorn Steel Company, Boston, Mass., acorporation of Massachusetts Application September 11, 1946, Serial No.696,168

3 Claims. (01. 76-101) Ifhis invention relates to a die stock forcutting dies, and more particularly to a die stock adapted for themanufacture of clicker dies.

The object of the invention is to provide a novel and improved die stockof novel crosssectional shape for cutting dies which may be sharpened byremoving by filing or grinding a relatively small amount of the edge ofthe stock to provide a cutting edge having relatively short bevelededges disposed with relation to the main body. portion of the die so asto provide an effective and substantial clearance between the cuttingedge of the die and the interior surface of the body portion of the die.

Another object of the invention is to provide a novel and superior diestock for cutting dies shaped in cross-section to provide edge portionsat the top and bottom of the die stocks which are flared inwardly beyondthe plane of the interior surface of the main and intervening bodyportion of the die whereby to enable cutting edges to be provided at thetop and bottom of the die stock which are disposed to provide efficientand substantial clearance between the cutting edge and the inner surfaceof the die stock.

With these general objects in view, and such others as may hereinafterappear, the invention consists in the die stock for cutting dieshereinafter described and particularly defined in the claims at the endof this specification.

In the drawings illustrating the preferred embodiments of the invention,Figs. 1 and 2 are cross-sectional views showing the present single anddouble edged die stock, respectively; Figs. 3 and 4 are similar viewsafter the cutting edges have been formed on the edges of the die stock;and Fig. 5 is a cross-sectional view of a modified form of the die stockembodying the present invention.

Referring now to the drawing, the present die stock may and preferablywill be provided in elongated strip form adapted to be bent to thedesired configuration and supported in a die holder with the ends joinedin abutting relation to form a die for dieing out blanks from sheetmaterial. The elongated strip of die stock may be formed in crosssection to provide a single edge or a double edge die, and as shown inFig. 1 the single edge die stock embodying the invention comprises astrip of steel having the general sectional shape shown in Fig. 1,wherein the body portion of the die stock comprises a thin strip ofsteel having parallel sides l2, 14 comprising the outer and inner sidesof the formed die respectively. The inner side or the side whichcomprises the interior surface in the completed die at one end is shapedto curve or flare inwardly as indicated at 15, and the outer side isshaped to provide a beveled surface 16 which cooperates with the flaredinner surface of the edge portion of the die to terminate in arelatively narrow edge portion 20. The beveled surface I6 is ofsubstantially greater length than the flared portion 15. A substantialportion of the edge portion 20 is disposed beyond the plane of the innersurface l4 of the die stock, thus permitting the edge portion to beeasily sharpened by the removal of a minimum amount of metal, as byfiling or grinding away the portions of the edge of the thus formed diestock between the dotted lines in Fig. 3 and the full lines to form acutting edge 2| which is disposed beyond the plane of the inner surfaceId of the completed die. The cutting edge 2| may thus be formed bygrinding or filing a minimum amount of metal, thus contributing to theease with which the die stock may be sharpened.

As shown in Figs. 2 and 4, the present die stock may be double-edgedwith the second and lower edge portion of the die stock similarly shapedto dispose a substantial portion of the edge of the die stock beyond theplane of the inner surface M of the main body portion of the die stockso that when sharpened, as shown in Fig. 4, the cutting edge 2| isdisposed beyond such plane.

During the use of the die stock the disposition of the cutting edgebeyond the plane of the inner surface of the die and the flaring portionof such inner surface adjacent the cutting edge serves to form aneffective clearance for the work being cut out.

In the preferred embodiment of the invention the bevel surface I6 is soarranged as to locate the outer edge 22 of the edge surface 20 of thedie stock in the plane of the inner surface M of the main body portionof the die stock, thereby causing the edge portion of the stock in theformed die to project inwardly beyond such plane to dispose the cuttingedge 2| sufficiently beyond the plane [4 to provide the requisiteclearance for the proper functioning of the die. Also, in practice, theflared surface l5 between the inner surface ll of the body portion andthe inner edge 21 of the edge 20 to be sharpened may and preferably willbe curved at a suitable radius, as illustrated, to form in effect aconcave surface disposed beyond the plane of the inner surface IQ of thebody portion.

The surfaces [2, l4 are preferably plane and vantage.

A 0.760" E 0.025 B 0.125" E. 0.240, C 0.125" G 0.280 D 0.025" H 0.125

In practice the cutting edge of the die maybe disposed to provideclearances of different amounts depending upon the kind of material tobe cut, and on the size of the die, and these clearances may vary from0.015. to inches.

Instead of the flared out portion I51 may prefer to provide a straightportion 25 in either the single edge or double edge die stock, and thismay be formed during the rolling of the steel strip forming the diestock by introducing a straight bend in the edge portion of the stripbeing-rolled on the last pass through the rolling mill; In Fig, 5 I haveillustrated such a construction ofdie stock, it being understood thatthe straight surface 25 may. be provided at either onejor both edges ofthe finished diev stock.

As used throughout. the claims the term flared is intended to cover anddefine both the curved surface l5, and the straight surface 25, and'while 'the preferred embodiment of the invention has been hereinillustrated and described, it will be understood that the invention maybe, embodied in other forms within the scope; of the following claims.

Having thus described the invention, what is claimedis:

1. Cutting die stock for forming clicker dies comprising a steel striphaving the main part of' the body portion thereof provided with straightand parallel sides comprising the inner andouter sides of a formed dieand having an edge part arranged to be sharpened, said strip beingflared. inwardly lengthwise of the strip adjacentvv the-edge to besharpened, said flared portionbeingdefined by an arc tangent to saidinner side and intersecting said edge part a substantial distanceinwardly beyond the inner side of said body portion, the opposite sideadjacent said edge part being provided with a straight bevelintersecting said edge part at a point substantially in alignment withthe plane of the inner side of the body portion.

2. Cutting die stock as defined in claim 1 wherein the width of the edgepart to be sharpened is substantially in the ratio of 1 to 5 withrespect to the thickness of said body portion.

3-. Cutting die stock for forming double-edged clicker dies comprising asteel strip having the main part ofthe body portion provided withstraight and parallel sides comprising the inner and outer sides of aformed die and having opposed edge partsarranged to be sharpened, saidstrip being flared inwardly lengthwise of the strip adjacent the edgesto be sharpened, each of said flared portions being defined by an arctangent to said inner side and intersecting said edge part a substantialdistance inwardly b eyond' the inner side of said body portion, theopposite side adjacent said edge part being provided with a straightbevel-intersecting said edge part at a point substantially in alignmentwith the plane of the inner side of said body portion.

EDWARD JOHNSON:

REFERENCES CITED The following references arev of record in the, file ofthis patent:

UNITED STATES PATENTS Number Name. Date 1,150,142 Prime Aug. 17, 19,151,986,139 Cumfer s Jan. 1, 1935 2,049,157 Deubel -g-- J ly 23,, 19.36,,2,150,437 Martin May 30, 1939, 2,170,166 Sweet Aug. 22, 1939, 2,211,213Lindholm Aug. 13, 1940, 2,293,041 Dedrick Oct. 6. 19 2 2,276,376. DeubelMar. r7, 19.42"

